
We are a low volume user, around 40 logins daily transferring 5 files. This is causing some of our ftp jobs to fail and need to be resent. If you have any more questions, don’t hesitate to leave a comment down below.We are experiencing occasional 421 Could not create socket notices. You might also want to check out our articles on solving FTP issues like solving error 421 – too many connections and ECONNREFUSED. Some routers and firewalls block FTP port 21 due to security reasons, so it’s essential to check the port’s connection before performing the File Transfer Protocol. If you happen to have an FTP connection issue, it’s essential to verify whether or not there’s a blockage in port 21. Unfortunately, some routers and firewalls block this port because hackers often target FTP servers via port 21. An FTP client cannot perform the protocol if it fails to connect to the FTP ports. In order to work correctly, FTP must use two ports - port 21 for command and control, and port 20 for data transport.

Since we’re be using a Telnet command to check the connection, you need to ensure that your operating system has Telnet Client enabled. If that’s the case, we recommend you to contact your ISP to open the port.

This same command applies to all operating systems. Make sure to change the domain name accordingly.

In this guide, we’ll show you how to check if your FTP port 21 is open.

Having issues connecting to your FTP account? If that’s the case, it’s worth checking whether port 21 is the culprit behind the connection failure.
